Starter Generator System for Tip Turbine Engine

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Solution Overview

Problem

Conventional turbofan engines have an elongated structure due to axial flow, making them difficult to package in certain applications, and they require a dedicated starter and generator with an accessory gearbox and operation in an oil environment, which adds weight and complexity.

Innovation Solution

A starter-generator system for a tip turbine engine with a fixed starter generator stator mounted to a static inner support housing and a starter generator rotor engaged with the axial compressor rotor, eliminating the need for an accessory gearbox and operation in an oil environment, and using a starter motor-generator that directly connects to the axial compressor rotor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a dedicated starter and generator with an accessory gearbox are used in a conventional turbofan engine, then the engine can achieve reliable starting and power generation, but the engine structure becomes elongated and heavier

Engineering Contradiction:

Improvestarting and power generation reliabilityVSAvoidengine longitudinal length

Core Design Contradiction:

ReliabilityVSLength of moving object

Solution Approach 1:

The patent combines the starter and generator into a single integrated starter-generator unit, and further merges this unit directly with the compressor rotor structure. This eliminates the need for a separate accessory gearbox and reduces the longitudinal length of the engine while maintaining reliable starting and power generation functions

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The compressor rotor serves multiple functions: it acts as both the compression element for air intake and as the mounting structure for the starter-generator system. This multi-functionality eliminates the need for separate dedicated starter and generator components, reducing overall engine length and weight

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If an accessory gearbox is used to mount the starter and generator, then the machines can be properly supported, but the engine weight and complexity increase

Engineering Contradiction:

Improvemachine support and operationVSAvoidaccessory gearbox and oil environment system

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the accessory gearbox from the engine system entirely. The starter-generator unit is directly mounted to the compressor rotor without requiring a gearbox intermediary, thereby removing the associated oil environment system and reducing overall device complexity

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical accessory gearbox system with a direct mechanical integration of the starter-generator to the compressor rotor. This substitution eliminates the need for gear trains, oil lubrication systems, and associated mechanical complexity while maintaining proper support and operation

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Power

If a conventional starter-generator system with gearbox is used, then adequate power transmission is achieved, but the system becomes heavier and more complex

Engineering Contradiction:

Improvepower transmission capabilityVSAvoidstarter-generator system weight

Core Design Contradiction:

PowerVSWeight of moving object

Solution Approach 1:

By merging the starter-generator unit directly with the compressor rotor, the patent eliminates the weight of the gearbox and associated components while maintaining adequate power transmission capability through the direct mechanical connection to the rotating mass

Inventive Principle:

Principle #5Merging (Combining)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution provides a lightweight starter-generator system that reduces the engine's length and weight, simplifies the design by eliminating the accessory gearbox, and operates without the need for an oil environment, enhancing packaging flexibility and reducing complexity.

Implementation Method 1

a starter motor with a fixed starter generator stator and a starter generator rotor

Methodology Applied

Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Implementation Method 2

a starter motor with a fixed starter generator stator and a starter generator rotor surrounds the fixed starter generator stator and is engaged with the axial compressor rotor

Methodology Applied

Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Data Source

PatentUS7874163B2Starter generator system for a tip turbine engine

Publication Date: 2011.01.25 RTX CORP

AI summary

A starter-generator system for a tip turbine engine includes a starter motor with a fixed starter generator stator and a starter generator rotor. The fixed starter generator stator is mounted to a static inner support housing. The starter generator rotor surrounds the fixed starter generator stator and is engagement with the axial compressor rotor.